Association of acylated cationic decapeptides with dipalmitoylphosphatidylserine-dipalmitoylphosphatidylcholine lipid membranes

Research output: Contribution to journalJournal articleResearchpeer-review

  • Tina B. Pedersen
  • Mads C. Sabra
  • Frøkjær, Sven
  • Ole G. Mouritsen
  • Kent Jørgensen

The interaction of three acylated and cationic decapeptides with lipid membranes composed of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylserine (DPPS) has been studied by means of fluorescence spectroscopy and differential scanning calorimetry (DSC). The synthetic model decapeptides that are N-terminally linked with C2, C8, and C14 acyl chains contain four basic histidine residues in their identical amino acid sequence. A binding model, based on changes in the intrinsic fluorescent properties of the peptides upon association with the DPPC-DPPS membranes, is used to estimate the peptide-membrane dissociation constants. The results clearly show that all three peptides have a higher affinity to liposomes containing DPPS lipids due to non-specific electrostatic interactions between the cationic peptides and the anionic DPPS lipids. Furthermore, it is found that the acyl chain length of the peptides plays a crucial role for the binding. A preference for fluid phase membranes as compared to gel phase membranes is generally observed for all three peptides. DSC is used to characterise the influence of the three peptides on the thermodynamic phase behaviour of the binary DPPC-DPPS lipid mixture. The extent of peptide association deduced from the heat capacity measurements suggests a strong binding and membrane insertion of the C14 acylated peptide in accordance with the fluorescence measurements.

Original languageEnglish
JournalChemistry and Physics of Lipids
Volume113
Issue number1-2
Pages (from-to)83-95
Number of pages13
ISSN0009-3084
DOIs
Publication statusPublished - 7 Nov 2001

    Research areas

  • Acylated peptide, Calorimetry, DPPC-DPPS lipid mixture, Peptide-membrane association, Tryptophan fluorescence

ID: 236896731